Development of a bienzymatic amperometric biosensor to determine uric acid in human serum, based on mesoporous silica (MCM-41) for enzyme immobilization

2014 ◽  
Vol 195 ◽  
pp. 58-62 ◽  
Author(s):  
Rodolfo Mundaca-Uribe ◽  
Francisca Bustos-Ramírez ◽  
Claudio Zaror-Zaror ◽  
Mario Aranda-Bustos ◽  
Jose Neira-Hinojosa ◽  
...  
2012 ◽  
Vol 25 (1) ◽  
pp. 308-315 ◽  
Author(s):  
Noemi Caro-Jara ◽  
Rodolfo Mundaca-Uribe ◽  
Claudio Zaror-Zaror ◽  
Jorge Carpinelli-Pavisic ◽  
Mario Aranda-Bustos ◽  
...  

2019 ◽  
Vol 15 (6) ◽  
pp. 678-684
Author(s):  
Biljana Nigović ◽  
Jakov Vlak

Background: High uric acid serum level, hyperuricemia, is now associated with many diseases such as gout, chronic kidney disease, hypertension, coronary artery disease and diabetes. Febuxostat is a novel selective xanthine oxidase inhibitor approved for the treatment of hyperuricemia. Objective: The aim of this study was to develop a first analytical method for the simultaneous determination of febuxostat and uric acid. Methods: An unmodified boron-doped diamond electrode provided concurrent quantitation of drug at low levels and uric acid, which has clinical significance in the diagnosis and therapy of hyperuricemia, at relatively high concentrations. The direct square-wave voltammetric method was applied to the analysis of both analytes in human serum samples. Results: Under the optimized conditions, the linear response of peak current on febuxostat concentration was achieved in the range from 7.5 × 10-7 to 3 × 10-5 M, while uric acid showed two linear ranges of 5 × 10-6 - 5 × 10-5 M and 5 × 10-5 - 2 × 10-4 M. The method was successfully utilised for quantification of both analytes in human serum samples. Good recoveries were obtained without interference from common inorganic cations and anions as well as glucose, dopamine, ascorbic and folic acids at concentrations expected in physiological conditions. Conclusion: The great benefits of developed method are fast analysis (only 7.5 s for run), low cost and simplicity of performance.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yige Guo ◽  
Bin Chen ◽  
Ying Zhao ◽  
Tianxue Yang

AbstractAntibiotics are emerging pollutants and increasingly present in aquaculture and industrial wastewater. Due to their impact on the environment and health, their removal has recently become a significant concern. In this investigation, we synthesized nano zero-valent iron-loaded magnetic mesoporous silica (Fe-MCM-41-A) via precipitation and applied the adsorption of oxytetracycline (OTC) from an aqueous solution. The effects of competing ions such as Na+, Ca2+ and Cu2+ on the adsorption process under different pH conditions were studied in depth to providing a theoretical basis for the application of nanomaterials. The characterization of the obtained material through transmission electron microscopy demonstrates that the adsorbent possesses hexagonal channels, which facilitate mass transfer during adsorption. The loaded zero-valent iron made the magnetic, and was thus separated under an applied magnetic field. The adsorption of OTC onto Fe-MCM-41-A is rapid and obeys the pseudo-second-order kinetic model, and the maximum adsorption capacity of OTC is 625.90 mg g−1. The reaction between OTC and Fe-MCM-41-A was inner complexation and was less affected by the Na+. The effect of Ca2+ on the adsorption was small under acidic and neutral conditions. However, the promotion effect of Ca2+ increased by the increase of pH. Cu2+ decreased the removal efficiencies continuously and the inhibitory effects decrease varied with the increase of pH. We propose that surface complexing, ion-exchange, cationic π-bonding, hydrogen bonding, and hydrophobicity are responsible for the adsorption of OTC onto Fe-MCM-41-A.


2001 ◽  
Vol 73 (12) ◽  
pp. 1993-1999 ◽  
Author(s):  
P. V. Climent ◽  
M. L. M. Serralheiro ◽  
M. J. F. Rebelo

An amperometric biosensor based on the enzyme polyphenoloxidase (PPO), which makes the bioelectrocatalysis of phenolic compounds, was developed and optimized using cathecol as substrate. Polyethersulphone membranes were used for enzyme immobilization. Polyphenoloxidase oxidizes monophenols (cresolase activity) and diphenols (catecholase activity) into the corresponding o-quinones; the o-quinones formed in the enzymatic catalysis are then reduced back to cathecol at ­200 mV (vs. Ag, AgCl) at a platinum electrode. The polyphenoloxidase immobilized was from commercial origin or extracted from mushrooms. p-Cresol and phenol substrates were also tested. Reproducibility, response time, linearity, sensitivity, and stability of the biosensor were studied.


2011 ◽  
Vol 143 (1) ◽  
pp. 174-179 ◽  
Author(s):  
Marília R. Mello ◽  
Delphine Phanon ◽  
Gleiciani Q. Silveira ◽  
Philip L. Llewellyn ◽  
Célia M. Ronconi

RSC Advances ◽  
2015 ◽  
Vol 5 (8) ◽  
pp. 5494-5500 ◽  
Author(s):  
Xin Yu Ming Dong ◽  
Yan Yan Li ◽  
Feng Wei ◽  
Yu Zhou ◽  
Shi Lu Zhou ◽  
...  
Keyword(s):  

Menthol could be adsorbed in as-synthesized MCM-41 at 373 K, open stored in ambient for 30 days and released at 333 K.


2014 ◽  
Vol 20 (26) ◽  
pp. 7916-7921 ◽  
Author(s):  
Daishun Ling ◽  
Liqian Gao ◽  
Jianpeng Wang ◽  
Mohammadreza Shokouhimehr ◽  
Jiahui Liu ◽  
...  

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